Giardia and Intestinal Parasites in Cats: Symptoms, Meds, and Disinfection Guide

In 1 Minute: The Essentials

• Key symptoms: Greasy, yellowish, unformed stools with a rancid smell, accompanied by visible strands of mucus or specks of blood.
• Transmission route: Ingesting microscopic fecal cysts from contaminated water, shared litter boxes, or grooming paws after stepping in infected feces.
• Standard therapy: Oral fenbendazole once daily for 5 consecutive days, or metronidazole prescribed strictly by a vet (avoiding feline neurotoxicity).
• Environmental decontamination: Bathing the cat's backend on the final treatment day and steam-cleaning or bleaching litter pans to kill resistant cysts.
• Emergency signs: Dehydration, skin tenting, lethargy, or repeated vomiting require immediate intravenous rehydration.

---

Clinical Signs of Feline Giardiasis

• Pale, voluminous, semi-liquid stools.
• Strikingly foul, sulfurous odor.
• Thick translucent mucus coating the feces.
• Weight loss despite a normal or ravenous appetite.
• Intermittent flare-ups alternating with normal bowel movements.

---

Eradicating Giardia from the Environment

Giardia cysts have a tough outer shell that survives in cool, damp environments for months. To break the cycle of self-reinfection:

1. Daily Litter Box Care: Empty completely daily during medication. Disinfect with steam cleaners (>65°C / 150°F) or a 1:10 diluted bleach solution.
2. Wash the Rear End: Wash the perineal area and paws with cat shampoo on day 5 of therapy to rinse off shed cysts.
3. Wash Bedding Hot: Wash cat blankets and cushions in hot cycles (60°C).

---

When to Seek Emergency Veterinary Care

Kittens and immunocompromised adult cats can rapidly progress to severe dehydration and electrolyte collapse requiring emergency IV fluid therapy.

Find your nearest clinic in our 24-hour emergency veterinarian directory.

---

Clinical Sources & Further Reading

• ESCCAP Guideline 06: Control of Intestinal Protozoa in Dogs and Cats.
• WSAVA Feline Gastroenterology Standards.